Apparatus for performing thermal mechanical testing of test specimens are known in the art. One such well-known machine is the Gleeble, manufactured by Duffers Scientific, Inc. located in Poestenkill, N.Y. The details of such a machine are disclosed in U.S. Pat. No. 5,195,378 issued to Ferguson, the disclosure of which is hereby incorporated by reference. The Gleeble has a testing zone in a testing station which is located adjacent to and displaced from peripheral equipment, including a control panel which actuates hydraulically operated jaws which grip the specimen to be tested. The Gleeble has a pair of jaws which engage with the specimen to be tested. One of the jaws is stationary, while the other is movable. The specimen to be tested is placed between the jaws and held in place until the movable jaw is moved to engage the specimen. The movable jaw of the Gleeble are intended to impart a significant force to the test specimen, thereby imparting a test strain to the specimen. In order to place the specimen properly between the jaws, it must be held in place while the movable jaw is moved toward the stationary jaw of the apparatus and contacts the specimen. The specimen may be of various shapes, such as planar or cylindrical. Thus, it will be readily recognized that maintaining the specimen in a proper position and orientation is critical.
The operation of the hydraulic jaws is controlled from the control panel which is located adjacent to, but displaced from the testing station portion of the testing machine. As a result, for single operator operation, the operation must hold the specimen in place with one hand while operating the jaw control buttons of the control panel with the other hand. Because the control panel is displaced from the testing station and typically oriented at an angle of about 120.degree. to the testing station, in operating the controls with one hand to move the movable jaw, the operator must look away from the testing station, while holding the specimen in the other hand.
In the past, in order to avoid possible injury to the fingers and heads of the Gleeble operator, the specimen was typically held in place by hand held tongs needle-nose pliers or other implements. This proved unsatisfactory, as the proper positioning and orientation of the specimen was difficult. As a result, it has become increasingly apparent that an improved specimen holder was desired, which would protect the user while still providing accurate positioning of the test specimen and being readily removed from the testing machine once the specimen is positioned.
There are various prior art holders and clamps for holding specimens. For example, U.S. Pat. Nos. 2,350,060 and 2,368,900 are directed to a compression testing jig having opposing T-shaped jaws which hold a specimen to be tested. The jig is not removable while the specimen is being tested. U.S. Pat. No. 1,428,868 is directed to a ring chuck having opposing spring biased jaws. U.S. Pat. No. 4,874,156 is directed to a vise having a spring biased jaw slidably engaging a fixed jaw. The vise is mounted so as to be released and moved to another work station. U.S. Pat. No. 4,915,273 is directed to a bow and gun holder having fixed and spring-biased holding plates. U.S. Pat. No. 3,057,032 is directed to a clamp for holding a flexible foam specimen for tensile testing having cam actuated spring biased gripping jaws for holding the specimen. U.S. Pat. No. 4,641,534 is directed to a holding device for aligning/holding tablet shaped specimens, the device having opposing jaws which can be spring-biased and are vertically movable for placing the specimen in a testing station.
None of these prior art devices provides ready ease of accurate alignment of a specimen between jaws of a testing machine, while also permitting ready removable of the holder by hand, while avoiding exposing the user's hand to the testing zone.